atw Vol. 63 (2018) | Issue 2 ı February
RESEARCH AND INNOVATION 112
1.3 The innovation
The main features of this software and
study can be summarized as follows:
Exposure from all pathways is
included- Ingestion pathways are
modelled in such a detailed way
that, translocation, -transfer between
soil-plant, and feed-animal, food processing
and storage, weathering, and
dilution in the plant are all taken into
account. Time dependency in radionuclide
transfer in the environment
considering food harvesting, sowing
times, feeding regimes, and the
growing up of a person are all taken
into account. Individual doses for
maximum and average individuals
and for four age groups are calculated.
Doses in the case of implementation
of countermeasures are calculated.
Collective doses for big cities can be
calculated. Two different methods for
stochastic risk modelling are applied.
A probabilistic module has also
been developed; namely, uncertainty
analysis can be performed (if applicable).This
study is regarded as unique
since. The model algorithms, which
the KIANA Advance Computational
Computer Code developed for this
study was based on IAEA safety report
series [Müller, H. and Pröhl, G., 1993],
has been modified; the KIANA
Advance Computational Computer
Code to be able to calculate inhalation
doses from resuspension, individual
doses in terms of both average and
maximum habits, collective doses and
late risks, and to utilize the recent
knowledge in the dose and risk assessment
area to the extent possible, such
as dose conversion factors and risk
coefficients etc.
The long-range transport model,
which the code/software developed
for this study was coupled with,
was also upgraded to increase the
number of pollutants modelled to
provide us easiness. Besides, extensive
uncertainty and sensitivity analyses
associated with 96 parameters have
been performed for this study. The
meteorological module in the existing
environmental emergency response
system is associated with 3-day-
Domestic forecast meteorological
data acquired through the State
Meteorological Directorate. The dispersion
model is the Developed AIREM
and DOZAE M model that has the
capability to predict trajectories,
concentration, and deposition patterns
in the case of nuclear accidents and
normal operations. However, doses,
risks, and activities in the food chain
are not calculated with the existing
system in IRAN. Since the newly
developed KIANA Advance Computational
Computer Code for this
study is compatible with the existing
system's dispersion code, it can easily
be integrated into it.
2.1 Atmospheric dispersion
models
Numerous radiation dose calculation
tools have been developed over the
years. They calculate trajectories,
atmospheric transport and dispersion,
age-dependent radiation doses, early
and late health risks, monetary costs
of the accidents, doses in the case
of implementation of emergency
actions, collective health risk, uncertainty
analysis etc. Atmospheric
dispersion methods in these tools
can be based on simple Gaussian or
numerical approaches. Short-range
dispersion models usually use
straight-line Gaussian plume model.
These models are appropriate if the
release is from a source that has
dimensions, which are small compared
to the distances at which concentrations
are to be estimated. For
example, for the distances out to
5-10 km from the source point, if the
terrain is relatively flat and has
uniform surface conditions in all
directions and if the atmospheric
conditions at the time and location of
the release completely control the
transport and diffusion of material
in the atmosphere short-range
atmospheric dispersion models are
preferred. Gaussian dispersion equations
should be used to estimate concentrations
up to the 80 km from the
source under ideal conditions of flat
terrain and no spatial variations of the
wind field. Consequently, for a countrywide
dispersion simulation, due to
topo graphy and dispersion area, the
straight-line Gaussian models can not
be appropriate tools. Therefore, longrange
atmospheric dispersion models
are used in this paper. Dose assessment
methodology in some aforementioned
short range codes neglects
ingestion pathway and calculation
of doses in the late phase of the accident.
These are coupled with simple
radiation dose modelling algorithm,
including only inhalation and external
radiation pathways i.e. HotSpot,
RASCAL and RTARC [Homann, S. G.,
2010, Mcguire, S. A., Ramsdell, Jr., J. V.
and Athey, G. F., 2007, Stubna M. and
Kusovska Z. 1993] All radiation dose
exposure pathways can be seen in
Figure 1.
Since short range codes generally
calculate short-term doses incurred
immediately after the accident and
recommend emergency protective
actions, such as intervention, sheltering
and iodine pills, and long-term
effects incurred from the ingestion
pathway are not generally calculated
with these types of codes. Some of
the codes having a Gaussian plume
methodology calculates ingestion
doses, but not in a dynamic or
| | Fig. 1.
Radiation Dose Exposure Pathways in KIANA Advance Computational Computer Code.
Research and Innovation
Design and Development of a Radio eco logical Domestic User Friendly Code for Calculation of Radiation Doses and Concentration due to Airborn Radio nuclides Release
A. Haghighi Shad, D. Masti, M. Athari Allaf, K. Sepanloo, S.A.H. Feghhi and R. Khodadadi
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